Improved error handling in iOS ADM to avoid race during init

webrtc/modules/audio_device/ios/audio_device_ios.h

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_MODULES_AUDIO_DEVICE_IOS_AUDIO_DEVICE_IOS_H_
 #define WEBRTC_MODULES_AUDIO_DEVICE_IOS_AUDIO_DEVICE_IOS_H_
 
 #include <AudioUnit/AudioUnit.h>
 
+#include "webrtc/base/criticalsection.h"

[pbos-webrtc, 2015/11/18 18:51:48]

Move to .cc file

[henrika_webrtc, 2015/11/19 12:04:19]

Done.

 #include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/thread_annotations.h"

[pbos-webrtc, 2015/11/18 18:51:48]

Move to .cc file

[henrika_webrtc, 2015/11/19 12:04:19]

Done.

 #include "webrtc/base/thread_checker.h"
 #include "webrtc/modules/audio_device/audio_device_generic.h"
 
 namespace webrtc {
 
 class FineAudioBuffer;
 
 // Implements full duplex 16-bit mono PCM audio support for iOS using a
 // Voice-Processing (VP) I/O audio unit in Core Audio. The VP I/O audio unit
 // supports audio echo cancellation. It also adds automatic gain control,
@@ skipping 121 matching lines @@
   void ClearPlayoutWarning() override {}
   void ClearPlayoutError() override {}
   void ClearRecordingWarning() override {}
   void ClearRecordingError() override {}
 
  private:
   // Uses current |playout_parameters_| and |record_parameters_| to inform the
   // audio device buffer (ADB) about our internal audio parameters.
   void UpdateAudioDeviceBuffer();
 
+  bool ActivateAudioSession();
+  bool DeactivateAudioSession();
+
   // Registers observers for the AVAudioSessionRouteChangeNotification and
   // AVAudioSessionInterruptionNotification notifications.
   void RegisterNotificationObservers();
   void UnregisterNotificationObservers();
 
   // Since the preferred audio parameters are only hints to the OS, the actual
   // values may be different once the AVAudioSession has been activated.
   // This method asks for the current hardware parameters and takes actions
   // if they should differ from what we have asked for initially. It also
   // defines |playout_parameters_| and |record_parameters_|.
   void SetupAudioBuffersForActiveAudioSession();
 
   // Creates a Voice-Processing I/O unit and configures it for full-duplex
   // audio. The selected stream format is selected to avoid internal resampling
   // and to match the 10ms callback rate for WebRTC as well as possible.
   // This method also initializes the created audio unit.
   bool SetupAndInitializeVoiceProcessingAudioUnit();
 
   // Restarts active audio streams using a new sample rate. Required when e.g.
   // a BT headset is enabled or disabled.
   bool RestartAudioUnitWithNewFormat(float sample_rate);
 
   // Activates our audio session, creates and initializes the voice-processing
   // audio unit and verifies that we got the preferred native audio parameters.
   bool InitPlayOrRecord();
 
   // Closes and deletes the voice-processing I/O unit.
-  bool ShutdownPlayOrRecord();
+  void ShutdownPlayOrRecord();
+
+  // Helper method for destroying the existing audio unit.
+  void DisposeAudioUnit();
 
   // Callback function called on a real-time priority I/O thread from the audio
   // unit. This method is used to signal that recorded audio is available.
   static OSStatus RecordedDataIsAvailable(
       void* in_ref_con,
       AudioUnitRenderActionFlags* io_action_flags,
       const AudioTimeStamp* time_stamp,
       UInt32 in_bus_number,
       UInt32 in_number_frames,
       AudioBufferList* io_data);
@@ skipping 90 matching lines @@
   void* audio_interruption_observer_;
   void* route_change_observer_;
 
   // Contains the audio data format specification for a stream of audio.
   AudioStreamBasicDescription application_format_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_DEVICE_IOS_AUDIO_DEVICE_IOS_H_